fix: stabilize storage and test coverage

backend/tests/api/test_migration.py

@@ -206,7 +206,14 @@ class TestDryRunMigration:
             resp = client.post("/api/migration/dry-run", json=self.SELECTION_PAYLOAD)
         assert resp.status_code == 200
         assert resp.json()["summary"]["selected_dashboards"] == 2
-        assert resp.json()["risk"] == {"score": 0, "level": "low", "items": []}
+        assert resp.json()["risk"] == {
+            "score": 0,
+            "level": "low",
+            "items": [],
+            "blockers": 0,
+            "warnings": 0,
+            "confirmations": 0,
+        }
 
     def test_identical_environments(self):
         mock_config = MagicMock()
@@ -255,7 +262,7 @@ class TestDryRunMigration:
         with patch("src.api.routes.migration.MigrationDryRunService", return_value=mock_dry_run):
             client = _make_client({get_config_manager: lambda: mock_config})
             resp = client.post("/api/migration/dry-run", json=self.SELECTION_PAYLOAD)
-        assert resp.status_code == 500
+        assert resp.status_code == 400
 
 
 # ── get_migration_settings ──

backend/tests/api/test_tasks.py

@@ -160,18 +160,22 @@ class TestListTasks:
         assert resp.status_code == 200
 
     def test_logs_cleared(self):
-        from src.core.task_manager import Task, TaskStatus
+        from src.core.task_manager import LogEntry, Task
+
         mock_tm = MagicMock()
-        mock_task = MagicMock(spec=Task)
-        mock_task.id = "task-1"
-        mock_task.logs = ["log_entry_1", "log_entry_2"]
+        mock_task = Task(
+            id="task-1",
+            plugin_id="backup",
+            logs=[LogEntry(message="log_entry_1"), LogEntry(message="log_entry_2")],
+        )
         mock_tm.get_tasks.return_value = [mock_task]
 
         from src.dependencies import get_task_manager
         client = _make_client({get_task_manager: lambda: mock_tm})
         resp = client.get("/api/tasks")
         assert resp.status_code == 200
-        assert mock_task.logs == []
+        assert resp.json()[0]["logs"] == []
+        assert len(mock_task.logs) == 2
 
 
 # ── get_task ──
@@ -181,15 +185,9 @@ class TestGetTask:
 
     def test_success(self):
         mock_tm = MagicMock()
-        from src.core.task_manager import Task, TaskStatus
-        mock_task = MagicMock(spec=Task)
-        mock_task.id = "task-123"
-        mock_task.plugin_id = "backup"
-        mock_task.status = TaskStatus.PENDING
-        mock_task.params = {}
-        mock_task.created_at = None
-        mock_task.user_id = "admin"
-        mock_task.input_request = None
+        from src.core.task_manager import Task
+
+        mock_task = Task(id="task-123", plugin_id="backup", user_id="admin")
         mock_tm.get_task.return_value = mock_task
 
         from src.dependencies import get_task_manager